A vibration motor includes a vibrator, a friction member, and a pressurizing unit. The vibrator includes projecting portions and is vibrated by application of a driving voltage. The projecting portions are arranged in vicinities of nodes of the vibration, respectively. The friction member has a sliding surface formed of a curved surface with which the projecting portions come into contact. The pressurizing unit pressurizes the vibrator against the friction member with a pressurizing force. When the vibrator is vibrated, a driving force is generated in a tangential direction of the sliding surface by the vibration to drive the friction member relative to the vibrator, and each of the projecting portions generates an elliptic motion by the vibration. The elliptic motion is generated with an inclination at a predetermined angle with respect to the curved surface of the sliding surface.

A vibration type motor includes a vibration plate configured to vibrate by a piezoelectric element, a friction member including a contact surface for the vibration plate, and configured to move relative to the vibration plate as the vibration plate vibrates, and an adhesive member provided on the contact surface of the friction member. The vibration plate includes a protrusion that protrudes toward a side opposite to the piezoelectric element. The protrusion includes a sidewall portion, at least one contact portion that contacts the contact surface, and a flat portion provided between the contact portion and the sidewall portion. The adhesive member has an opening that avoids a moving range of the contact portion. The opening in the adhesive member is located outside the sidewall portion. An end of the adhesive member is located outside the friction member

A vibration-type actuator includes a vibrating body including an annular elastic member and an electric-mechanical energy conversion element, and an annular contact body configured to move relative to the vibrating body. The contact body includes a base portion, a support portion annularly extending from the base portion in a radial direction of the contact body, and a friction member provided at the support portion, formed separately from the support portion, and being in contact with the vibrating body. The friction member includes a first part extending in a direction along a central axis of the annular contact body, and a second part extending in the radial direction, the first part and the second part being connected to the support portion. The first part includes a portion that is connected by being either internally or externally fitted to the support portion in the radial direction.

A vibration wave motor comprises: an electromechanical conversion element; an elastic body which has a drive surface on which a vibration wave is generated due to vibration of the electromechanical conversion element; and a relative motion member which makes contact with the drive surface of the elastic body and is configured to rotationally drive by the vibration wave, the electromechanical conversion element having a density of from 4.2 to 6.0×10.sup.3 kg/m.sup.3, a plurality of grooves being provided on the drive surface side of the elastic body, and a value of T/(B+C) being within a range of from 1.3 to 2.8 when: depth of at least one groove of the plurality of grooves is defined as T; thickness from a base unit of the groove to a first surface is defined as B; and thickness of the electromechanical conversion element is defined as C.

A piezoelectric drive device includes a piezoelectric element, a vibrating plate with a concave portion provided in a side surface, and a projecting portion provided between two side surfaces of the concave portion and having a spherical shape, an elliptical shape, or an egg shape, wherein a plurality of the piezoelectric elements and a plurality of the vibrating plates are stacked, and the concave portion includes a bottom surface.

Provided is a vibration wave motor including: a vibrator; a friction member that comes into frictional contact with the vibrator; a press member that pressurizes the vibrator and the friction member into frictional contact with each other; a first guide member and a second guide member that guide the vibrator and the friction member so as to allow relative movement of the vibrator and the friction member; a hold member that holds the friction member and the first guide member; and a fixing member. The friction member and the first guide member are fixed to the hold member with the fixing member.

In a vibration type motor, a vibrator unit including a vibrator configured to vibrate, and a friction member unit including a friction member which the vibrator contacts relatively moving in a first direction. The vibrator unit is displaceable relative to the friction member unit in a second direction orthogonal to the first direction, and presses the vibrator against the friction member in the second direction. The friction member unit includes a stopper that contacts the vibrator unit so as to restrict the vibration unit from displacing, by an amount exceeding a predetermined amount, in the second direction. The stopper extends in the first direction, a distance greater than a length, in the first direction, of an area of the friction member which the vibrator contacts, and the stopper projects from the friction member toward the vibrator in the second direction when viewed from the first direction.

A hollow-cylindrical ultrasonic actuator is disclosed a central axis, an inner peripheral surface facing the central axis and an outer peripheral surface facing away from the central axis and spaced apart from the inner peripheral surface, a closed inner contour curve, a closed outer contour curve, at least one electrode, and an electromechanical material provided between opposed electrodes. In a non-actuated state of the ultrasonic actuator, a curvature of the inner contour curve or of an outer contour curve includes at least three mutually spaced-apart local maximum points.

A vibration actuator includes a vibrator including a shaft, an output transmission member penetrated by the shaft, and configured to rotate about the axis of the shall, and a fixed member configured not to move relative to the shaft and configured to move relative to the output transmission member. The fixed member includes a base portion and a projection portion protruding from the base portion to the output transmission member side, the vibration actuator includes a pressure reception member between the base portion and the output transmission member in an axial direction of the shaft, and wherein the projection portion and the output transmission member are in contact with each other in a direction orthogonal to the axial direction of the shaft, and the projection portion and the output transmission member are not in contact with each other in the axial direction of the shaft.

In a driving apparatus, a movable part is attached to a fixed part so that the movable part is restricted from displacing in a second axial direction and from rotating in a first rotating direction, and the movable part is allowed to move in a first axial direction, to displace in a third axial direction, and to rotate in a second rotating direction. The movable part is connected to a driven member movable in the first axial direction so that the movable part is allowed to displace in the second axial direction and to rotate in the first rotating direction, and restricted from displacing in the third axial direction and from rotating in the second rotating direction.